The present invention relates generally to tray handling equipment for removing filled or partially filled trays from a mail sorter and replenishing the mail sorter with empty trays. The invention is particularly useful with flats mail sorters.
Flats mail sorters are known and are commercially available. Flats mail sorters sort flat mail, such as magazines, large envelopes and the like, and discharge the sorted mail into trays. Each of these trays may be devoted to a particular mail distribution center, carrier route, delivery point, zip code or the like. Typically, a mail sortation system includes one or more rows of multiple sorter units. Examples of flats mail sorters include models FSM100 and TOPS 2000, marketed in the United States by Rapistan Systems of Atecs Mannesmann AG. As the mail is sorted, the filled or partially filled trays must be removed from the location at the particular sorter and replaced with an empty tray. Occasionally, there is also a requirement that a sweep operation be performed, whereby all of the trays are removed from their respective locations, even if the trays are only partially filled. Empty trays are then stocked at each of the sorters.
The removal of filled or partially filled trays and replacement with empty trays is traditionally performed manually. One or more operators must manually remove the at least partially filled tray from each of the multiple sorters and replace it with an empty tray, such that the sorter may continue the sortation process. Accordingly, the operation of the sorting machines is quite labor intensive.
A system has been proposed which includes a shuttle cart that travels underneath the chutes of the mail sorter units and carries multiple trays thereon. The trays are hoisted up into position beneath an appropriate sorter unit and locked or clamped in position at the sorter unit, so the cart may move to another sorter unit. Once filled, the trays are grabbed and moved down onto a shuttle cart for transporting the tray from the sorter unit. Such a system requires a rigid tray that is strong enough to withstand the clamping of the tray during the filling process. The system is also slow to provide empty trays to the sorter units and to move the full trays away from the sorter units.
Therefore, it is desirable to automate the manual processes of providing an empty tray to a sorter and/or removing an at least partially filled tray from the sorter.